The wireless local area network (hereinafter abbreviated WLAN) technology standard was established by IEEE (institute of electrical and electronics engineers) 802.11 standardization. IEEE 802.11a/b in IEEE 802.11 standard uses a band on 2.4 GHz or 5 GHz and provides a data rate of 11 Mbps (IEEE 802.11b) or 54 Mbps (IEEE 802.11a). IEEE 802.11g applies OFDM (orthogonal frequency division multiplexing) to provide a data rate of 54 Mbps. IEEE 802.11n applies MIMO-OFDM scheme to provide a data rate of 300 Mbps. The IEEE 802.11n uses maximum 40 MHz channel bandwidth to provide a data rate of maximum 600 Mbps.
As the pool of WLAN expands and WLAN-adopted applications are diversified, the demand for a new WLAN system supportive of performance higher than that supported by 802.11n standard is increasingly rising. VHF (very high frequency) WLAN system is one of IEEE 802.11 WLAN systems recently proposed to support a data processing speed of 1 Gbps or higher. For the standardization of VHT WLAN system, many ongoing efforts are made to research and develop such a scheme as PLCP (physical layer convergence procedure) format and the like to efficiently support 8×8 MIMO, channel bandwidths of 80 MHz or higher and coexistence of stations (e.g., VHT-STA, HT-STA, Legacy-STA, etc.) by IEEE 802.11 ac Work Group.
Moreover, ongoing standardization of regulating WLAN on TV idle band (i.e., white space) is made into 802.11af. The TV idle band (white space) includes a channel assigned to a broadcast channel allowed to be used by a licensed wireless device and mainly means a band between 512˜698 MHz.